Gas separation device

Abstract

To provide a gas separation device where the concentration of a specified gas component on the surface of a gas separation membrane is kept high and the degradation of separation efficiency is suppressed.SOLUTION: A gas separation device is characterized by having: a first gas chamber having a first wall part to define a first space, a mixed gas supply port disposed at the first wall part and supplying a mixed gas to the inside of the first space and a mixed gas exhaust port to exhaust the mixed gas from the inside of the first space to the outside; a second gas chamber having a second wall part to define a second space and a gas component exhaust port provided at the second wall part and exhausting a prescribed gas component contained in the mixed gas from the inside of the second space to the outside; and a rotary fan having a hollow base part rotating around a rotation shaft and having the inside communicating with the second space, a hollow blade part arranged in the first space and having the inside communicating with the second space and a first gas separation membrane which separates the inside of the blade part from the outside and passes the prescribed gas component therethrough.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gas separation device. [Background technology]

[0002] To achieve carbon neutral or carbon negative, technologies are being considered for capturing and capturing carbon dioxide emitted from thermal power plants, boiler facilities, etc., and carbon dioxide in the atmosphere. One known technology for this purpose is the membrane separation method, which separates carbon dioxide using a gas separation membrane.

[0003] For example, Patent Document 1 discloses a carbon dioxide recovery device having a first separation section that is arranged to separate a first supply space and a first processing space and separates carbon dioxide contained in a raw material gas supplied to the first supply space from impurity gases containing components of the raw material gas other than carbon dioxide by permeation. It also discloses that the first separation section includes a separation membrane that selectively permeates carbon dioxide contained in the raw material gas. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2021-133354 A Summary of the Invention [Problem to be solved by the invention]

[0005] In membrane separation, the challenge is to increase the separation efficiency of a specific gas component. In order to increase the separation efficiency of a gas separation membrane, it is necessary to maintain a high concentration of the specific gas component on the upstream side of the gas separation membrane. However, when the specific gas component permeates the gas separation membrane, the concentration on the upstream side decreases accordingly, resulting in a decrease in separation efficiency.

[0006] Therefore, there is a demand for a gas separation device that is less likely to lose concentration even when a specific gas component permeates a gas separation membrane, and that can suppress a decrease in separation efficiency. [Means for solving the problem]

[0007] A gas separation device according to an application example of the present invention includes: a first gas chamber including a first wall portion defining a first space, a mixed gas supply port provided in the first wall portion for supplying a mixed gas into the first space, and a mixed gas discharge port for discharging the mixed gas from the inside of the first space to the outside; a second gas chamber including a second wall portion defining a second space and a gas component exhaust port provided in the second wall portion and configured to exhaust a gas containing a predetermined gas component extracted from the mixed gas from the inside of the second space to the outside; a rotary fan that rotates about a rotation axis and has a hollow base, the interior of which communicates with the second space, a hollow blade portion that is disposed in the first space and the interior of which communicates with the second space, and a first gas separation membrane that separates the inside and outside of the blade portion and allows a gas having a higher concentration of the predetermined gas component than the mixed gas to pass through; Equipped with. [Brief description of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a configuration of a gas separation device according to a first embodiment. [Diagram 2] 2 is a plan view showing a rotary fan provided in the gas separation device of FIG. 1. FIG. [Diagram 3] 4 is a graph showing the relationship between the gas permeability of carbon dioxide through a first gas separation membrane and the concentration of carbon dioxide on the surface of the first gas separation membrane on the first space side. [Figure 4] FIG. 4 is a cross-sectional view showing the configuration of a gas separation device according to a second embodiment. [Diagram 5] 5 is a cross-sectional view showing a rotary fan provided in the gas separation device of FIG. 4. [Figure 6] FIG. 11 is a cross-sectional view showing the configuration of a gas separation device according to a third embodiment. [Figure 7] 7 is a plan view showing a rotary fan provided in the gas separation device of FIG. 6. FIG. [Figure 8] FIG. 11 is a plan view showing a rotary fan provided in the gas separation device according to the fourth embodiment. [Figure 9] FIG. 9 is a schematic diagram in which an example of the flow of mixed gas is added to the cross-sectional view of the wing portion shown in FIG. 8. [Figure 10] FIG. 10 is a schematic diagram in which an example of a flow of mixed gas is added to a cross-sectional view of a model (conventional model) in which the convex structures shown in FIG. 9 are omitted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a gas separation device of the present invention will be described in detail based on an embodiment shown in the accompanying drawings. 1. First embodiment First, the gas separation device according to the first embodiment will be described.

[0010] Fig. 1 is a cross-sectional view showing the configuration of a gas separation device 1 according to the first embodiment. Fig. 2 is a plan view showing a rotary fan 4 provided in the gas separation device 1 of Fig. 1.

[0011] In each figure of the present application, a z-axis and an r-axis are set. The r-axis is an axis that represents the radial direction when the z-axis is the center. Therefore, there are multiple r-axes that extend radially from the z-axis, but each figure shows one or two representative r-axes. In each figure, each axis is represented by an arrow, with the tip of the arrow being "plus" and the base of the arrow being "minus". In the following explanation, for example, "z-axis direction" includes both the plus and minus directions of the z-axis. The same applies to the r-axis direction.

[0012] 1.1. Overview The gas separation device 1 shown in FIG. 1 includes a first gas chamber 2, a second gas chamber 3, a rotary fan 4, and an exhaust pump 9.

[0013] The first gas chamber 2 has a first space S1. The first space S1 is configured such that the mixed gas G1 passes through it. The second gas chamber 3 has a second space S2. The second space S2 is configured such that the mixed gas G2 (a gas with a higher carbon dioxide concentration than the mixed gas G1) extracted and separated from the mixed gas G1 permeates through it. The carbon dioxide concentration satisfies G1 < G2. In each figure of the present application, the flow of the mixed gas G1 is represented by a solid arrow, and the flow of the mixed gas G2 is represented by a dashed arrow.

[0014] The mixed gas G1 is a gas containing carbon dioxide, which is the gas component to be separated, and other gas components (non-target components). The mixed gas G1 is not particularly limited, and for example, it is air, exhaust gas discharged from facilities such as factories, etc. The gas component to be separated is not limited to carbon dioxide and may be other gas components. The non-target components vary depending on the mixed gas G1. When the mixed gas G1 is air, they are nitrogen, oxygen, etc.

[0015] The rotary fan 4 has a hollow base 41 extending along the z-axis, a hollow blade part 42 disposed in the first gas chamber 2, and a first gas separation membrane 51 disposed on the blade part 42. The base 41 rotates around a rotation axis AR extending parallel to the z-axis, and its interior communicates with the second gas chamber 3. The blade part 42 is supported on the outer surface of the base 41, and its interior communicates with the second gas chamber 3. The first gas separation membrane 51 separates the interior (second space S2) and the exterior (first space S1) of the blade part 42, selectively or preferentially permeates carbon dioxide contained in the mixed gas G1 in the first space S1 over other gas components, and introduces a mixed gas G2 with a higher carbon dioxide concentration than the mixed gas G1 into the second space S2.

[0016] In such a gas separation device 1, the rotary fan 4 rotates, and thereby the blade portion 42 having the first gas separation membrane 51 moves in the mixed gas G1. Specifically, the rotary fan 4 generates an airflow from the positive side of the z-axis toward the negative side of the z-axis. Therefore, even if the concentration of carbon dioxide on the surface of the first gas separation membrane 51 on the first space S1 side decreases due to the action of the first gas separation membrane 51, the airflow can quickly supply new mixed gas G1 to the first gas separation membrane 51. That is, the blade portion 42 moves to an area where the concentration of carbon dioxide in the mixed gas G1 has not decreased, and thus the decrease in the concentration of carbon dioxide on the first gas separation membrane 51 can be suppressed. As a result, the decrease in the separation efficiency of carbon dioxide in the first gas separation membrane 51 can be suppressed.

[0017] 1.2.First gas chamber The first gas chamber 2 has a first wall portion 21, a mixed gas supply port 22, and a mixed gas discharge port .

[0018] The first wall portion 21 has an inner wall surface that defines a first space S1. A mixed gas G1 is supplied to the first space S1 through a mixed gas supply port 22. The supplied mixed gas G1 moves through the first space S1 by the rotary fan 4 and is discharged to the outside through a mixed gas discharge port 23. In this manner, the first space S1 controls the flow of the mixed gas G1. The material of the first wall portion 21 is not particularly limited, and examples of the material include a resin material, a metal material, and a ceramic material. Alternatively, the first wall portion 21 may be a composite material containing these materials.

[0019] The first wall portion 21 is provided with a mixed gas supply port 22 and a mixed gas discharge port 23 . The mixed gas supply port 22 is provided in a portion of the first wall portion 21 on the z-axis positive side of the rotary fan 4 (on an extension of the rotation axis AR). By providing the mixed gas supply port 22 in such a portion, new mixed gas G1 can be efficiently drawn into the first space S1 along with the airflow generated by the rotary fan 4.

[0020] The mixed gas exhaust port 23 is provided in a portion of the first wall portion 21 on the positive side of the r-axis of the rotary fan 4 (on the radius of the rotation axis AR). The radius of the rotation axis AR refers to a half line perpendicular to the rotation axis AR. By providing the mixed gas exhaust port 23 in such a portion, the mixed gas G1 with a reduced carbon dioxide concentration can be efficiently exhausted to the outside of the first space S1 along with the airflow generated by the rotary fan 4.

[0021] The mixed gas supply port 22 may be configured as a hole that communicates the first space S1 with the outside, or may have a structure to which a pipe (not shown) can be connected.

[0022] The mixed gas outlet 23 may be configured as a hole that connects the first space S1 to the outside, or may have a structure to which a pipe (not shown) can be connected.

[0023] 1.3.Second gas chamber The second gas chamber 3 has a second wall portion 31 and a gas component discharge port 33 .

[0024] The inner wall surface of the second wall portion 31 defines the second space S2. The separated carbon dioxide is supplied to the second space S2. The supplied carbon dioxide moves through the second space S2 and is exhausted by the exhaust pump 9 through the gas component exhaust port 33. The exhausted carbon dioxide is collected in a collection section (not shown). The material constituting the second wall portion 31 is not particularly limited as long as it is a material having the rigidity to withstand the air pressure difference between the second space S2 and the outside, and examples of the material include resin materials, metal materials, and ceramic materials. Alternatively, the material may be a composite material containing these materials.

[0025] The gas component outlet 33 is connected to the exhaust pump 9 via a pipe. This allows the pressure in the second space S2 to be reduced, and carbon dioxide to be separated. Examples of the exhaust pump 9 include dry pumps such as screw pumps and scroll pumps, oil rotary pumps, and turbo molecular pumps. Of these, dry pumps are preferably used, and screw pumps are more preferably used. These pumps are useful as the exhaust pump 9 because they do not use oils or liquids, so there is no risk of contaminating the second space S2, and they consume low power.

[0026] A part of the first wall 21 and the second wall 31 is integral with each other. This part is provided with a communication hole 212 and a communication hole 214 that communicate between the first space S1 and the second space S2.

[0027] A plurality of communication holes 212 are provided at equal intervals around the rotation axis AR. The communication holes 212 are closed by the second gas separation membrane 52. The second gas separation membrane 52 separates the second space S2 from the first space S1, and selectively allows carbon dioxide contained in the mixed gas G1 in the first space S1 to permeate therethrough with priority over other gas components, thereby introducing the mixed gas G2 having a higher concentration of carbon dioxide than the mixed gas G1 into the second space S2.

[0028] A base 41 of the rotary fan 4, which will be described later, is inserted into the communication hole 214. The first gas chamber 2 described above has a sealed bearing 24. The sealed bearing 24 airtightly connects the communication hole 214 and the base 41. This allows the rotary fan 4 to be rotatably supported relative to the first gas chamber 2, and also makes it possible to maintain the air pressure difference between the first space S1 and the second space S2.

[0029] 1.4. Rotating Fan 1 and 2 is an axial fan having a base 41, blades 42, and a first gas separation membrane 51. An axial fan is a fan that generates an airflow along the extension direction of the rotation axis AR (z-axis direction).

[0030] 1.4.1. Base The base 41 has a cylindrical shape extending along the rotation axis AR. The end of the base 41 on the z-axis positive side is closed. The hollow interior of the base 41 communicates with the second space S2. The base 41 has the rigidity required to support the wing portion 42, the rigidity to withstand the air pressure difference between the first space S1 and the second space S2, and sufficient airtightness. The material of the base 41 is not particularly limited, and examples of the material include a resin material, a metal material, and a ceramic material. Alternatively, the base 41 may be a composite material containing these materials.

[0031] 1.4.2. Wings The wing portion 42 extends in a direction intersecting the rotation axis AR and has a plate shape. The wing portion 42 is hollow. An opening is provided on each of the surface (first surface) on the z-axis positive side and the surface (second surface) on the z-axis negative side of the wing portion 42. A first gas separation membrane 51 is disposed so as to close the opening. The hollow interior of the wing portion 42 communicates with the second space S2 via the interior of the base 41. The wing portion 42 has a rigidity capable of withstanding the air pressure difference between the first space S1 and the second space S2, and has sufficient airtightness. The material of the wing portion 42 is not particularly limited, and examples thereof include a resin material, a metal material, and a ceramic material. The wing portion 42 may also be a composite material containing these materials.

[0032] The blades 42 may be integral with the base 41, but are preferably detachable from the base 41. This allows the blades 42 to be easily removed and attached during maintenance of the rotary fan 4, improving maintainability.

[0033] Wing portion 42 has a trapezoidal shape when viewed from above rotation axis AR, as shown in Fig. 2. Wing portion 42 has an upper base (the base end of wing portion 42) connected to the side of base 41, and a lower base (the tip of wing portion 42) which is a free end. Note that the shape of wing portion 42 is not limited to a trapezoid, and may be another shape.

[0034] The number of blades 42 of the rotary fan 4 may be one, but is preferably multiple, more preferably 4 to 100, and even more preferably 6 to 20. By having multiple blades 42, a gas separation device 1 with a particularly large gas permeation rate of carbon dioxide can be realized. If the number of blades 42 is below the lower limit, the gas permeation rate of carbon dioxide may be reduced. On the other hand, the number of blades 42 may be above the upper limit, but the weight of the rotary fan 4 may increase, and the energy required for rotation may increase.

[0035] In FIG. 2, eight blades 42 are arranged at equal intervals around the rotation axis AR. When viewed from above the rotation axis AR, the blades 42 may overlap each other, but it is preferable that the blades 42 are offset from each other. This makes it difficult for the airflow to stagnate in the z-axis direction. In addition, when the mixed gas G1 is supplied from the positive side of the z-axis, it is possible to ensure equal opportunities for contact between the mixed gas G1 and the first gas separation membrane 51. As a result, it is possible to sufficiently increase the carbon dioxide separation efficiency in each first gas separation membrane 51.

[0036] The outer diameter D of the rotary fan 4 is not particularly limited, but is preferably 50 mm or more and 5000 mm or less, and more preferably 200 mm or more and 1000 mm or less. This makes it possible to optimize the balance between the energy required to rotate the rotary fan 4 and the amount of carbon dioxide gas permeating through the rotary fan 4.

[0037] The thickness t of the blade 42 is appropriately set according to the size of the blade 42 and is not particularly limited, but is preferably 0.1 mm to 200 mm, more preferably 0.5 mm to 100 mm, and even more preferably 1 mm to 30 mm. This makes it possible to optimize the balance between the energy required to rotate the rotary fan 4 and the rigidity of the blade 42.

[0038] The blade portion 42 may extend from the base portion 41 toward the r-axis positive side, but it is preferable that the first gas separation membrane 51 extends so as to be inclined with respect to the rotation axis AR. Specifically, when the first gas separation membrane 51 is cut on a plane including the rotation axis AR, the angle θ (angle on the second space S2 side) between the rotation axis AR and the cut surface of the first gas separation membrane 51 may be 90°, but is preferably greater than 0° and less than 90°. That is, in the example shown in FIG. 1, the tip of the blade portion 42 is displaced toward the z-axis negative side from the base end. This makes it possible to generate a stronger airflow toward the z-axis negative side in the first space S1 when the blade portion 42 rotates around the rotation axis AR. As a result, the mixed gas G1 with a low concentration of carbon dioxide is ejected toward the r-axis positive side and moved to the mixed gas outlet 23, and new mixed gas G1 with a high concentration of carbon dioxide is drawn into the rotary fan 4.

[0039] Moreover, the angle θ between the rotation axis AR and the cut surface of the first gas separation membrane 51 is more preferably 20° or more and 80° or less, and further preferably 30° or more and 70° or less.

[0040] The blade portion 42 may have a plate shape, and may be either a flat plate shape or a curved plate shape. The blade portion 42 may be twisted around the r axis shown in FIG. 2. Specifically, the blade portion 42 may be arranged so that the normal to the surface of the first gas separation membrane 51 and the rotation axis AR intersect with each other, or may be arranged so that they are in a twisted relationship. In the latter case, a larger volume of airflow can be generated by optimizing the direction and angle of the twist.

[0041] 1.4.3. First gas separation membrane The first gas separation membrane 51 separates the inside and outside of the blade portion 42 and allows the mixed gas G2, which has a higher concentration of carbon dioxide than the mixed gas G1, to pass through. When the rotary fan 4 rotates, the first gas separation membrane 51 moves in the mixed gas G1. At this time, the first gas separation membrane 51 preferentially passes the carbon dioxide on the first space S1 side compared to gas components other than carbon dioxide contained in the mixed gas G1, and separates it to the second space S2 side. As a result, although the concentration of carbon dioxide on the first space S1 side decreases, the blade portion 42 moves to an area where the concentration of carbon dioxide in the mixed gas G1 has not decreased, that is, an area where the new mixed gas G1 exists, so that the decrease in the concentration of carbon dioxide on the surface of the first space S1 side of the first gas separation membrane 51 can be suppressed. As a result, the decrease in the separation efficiency of carbon dioxide in the first gas separation membrane 51 can be suppressed. The new mixed gas G1 refers to the mixed gas G1 in which the concentration of carbon dioxide has hardly decreased and has the original concentration.

[0042] 1 is provided with two first gas separation membranes 51. The number of first gas separation membranes 51 provided on one wing portion 42 may be one, but preferably multiple. By providing multiple first gas separation membranes 51, a gas separation device 1 with a particularly large gas permeation rate for carbon dioxide can be realized.

[0043] When a plurality of first gas separation membranes 51 are provided, the first gas separation membranes 51 may have the same configuration as each other, or may have different configurations.

[0044] The first gas separation membrane 51 selectively allows carbon dioxide contained in the mixed gas G1 supplied to the first space S1 side to permeate to the second space S2 side preferentially over other gas components. Therefore, the first gas separation membrane 51 has a property that the gas permeability of carbon dioxide is higher than the gas permeability of non-target components (the property that the gas selectivity ratio of carbon dioxide is high). Hereinafter, the ratio of the gas permeability of carbon dioxide to the gas permeability of nitrogen will be simply referred to as the "gas selectivity ratio."

[0045] The gas selectivity ratio of the first gas separation membrane 51 is preferably 3 or more, and more preferably 10 or more and 1000 or less. When the gas selectivity ratio is within the above range, the first gas separation membrane 51 can efficiently separate and recover carbon dioxide in the mixed gas G1.

[0046] The nitrogen gas permeability of the first gas separation membrane 51 and the carbon dioxide gas permeability of the first gas separation membrane 51 are each measured in accordance with the gas permeability test method (Part 1: differential pressure method) specified in JIS K 7126-1:2006. A gas permeability measuring device is used for the measurement. An example of the gas permeability measuring device is GTR-11A / 31A manufactured by GTR Tech Co., Ltd. In this device, the gas that has permeated the first gas separation membrane 51 is introduced into a gas chromatograph, and the gas permeability of each component is measured.

[0047] In the first gas separation membrane 51, the gas permeability of carbon dioxide is preferably 1000 GPU or more, more preferably 5000 GPU or more and 100,000 GPU or less, and even more preferably 10,000 GPU or more and 50,000 GPU or less. This makes it possible to reduce the amount of energy input required for separation, specifically, to realize a first gas separation membrane 51 that can reduce the pressure difference between the first space S1 side and the second space S2 side. If the gas permeability of carbon dioxide of the first gas separation membrane 51 falls below the lower limit, a lot of energy is required to separate carbon dioxide, and the economic efficiency of the operation of the gas separation device 1 may decrease. On the other hand, if the gas permeability of carbon dioxide of the first gas separation membrane 51 exceeds the upper limit, the cost of manufacturing the first gas separation membrane 51 may increase. 1 GPU is 3.35×10 -10 mol m -2 ·s -1 ·Pa -1 It is.

[0048] Fig. 3 is a graph showing the relationship between the carbon dioxide gas permeability of the first gas separation membrane 51 and the carbon dioxide concentration on the surface on the first space S1 side of the first gas separation membrane 51. The graph shown in Fig. 3 plots the carbon dioxide concentration one second after the mixed gas G1 is supplied when the flow rate of the mixed gas G1 supplied onto the surface on the first space S1 side is zero. The gas selectivity of the first gas separation membrane 51 is also assumed to be infinite.

[0049] 3, when the carbon dioxide gas permeability of the first gas separation membrane 51 becomes 1000 GPU or more, the carbon dioxide concentration drops sharply. For this reason, when the gas permeability is 1000 GPU or more, the carbon dioxide concentration on the surface on the first space S1 side becomes particularly important in increasing the carbon dioxide separation efficiency in the first gas separation membrane 51.

[0050] The thickness of the first gas separation membrane 51 is not particularly limited, but is preferably 1 nm to 1000 μm, more preferably 5 nm to 100 μm, and even more preferably 10 nm to 10 μm.

[0051] The average thickness of the first gas separation membrane 51 is the average value of thicknesses measured at 10 points on the first gas separation membrane 51. The thickness of the first gas separation membrane 51 can be measured using, for example, a thickness gauge.

[0052] Although the size of the first gas separation membrane 51 is not particularly limited, the maximum length is preferably 5 cm to 2 m, and more preferably 10 cm to 1 m. This provides a first gas separation membrane 51 that has mechanical strength sufficient to withstand pressure differences and can ensure a sufficient gas permeability.

[0053] The first gas separation membrane 51 may be a single layer or a composite layer formed by laminating multiple layers. If it is a composite layer, the first gas separation membrane 51 may include a porous layer that is porous.

[0054] Examples of the constituent material of the first gas separation membrane 51 include a polymer material, a ceramic material, a metal material, etc. Furthermore, the constituent material of the first gas separation membrane 51 may be a composite material of these materials or a composite material of these materials and another material.

[0055] Examples of polymeric materials include polyolefin resins such as polyethylene and polypropylene, fluorine-containing resins such as polytetrafluoroethylene, polyvinyl fluoride and polyvinylidene fluoride, organopolysiloxane (silicone resin), polystyrene, cellulose, cellulose acetate, polyurethane, polyacrylonitrile, polyphenylene oxide, polysulfone, polyethersulfone, polyimide, polyaramid, nylon, and the like.

[0056] Examples of the ceramic material include alumina, cordierite, mullite, silicon carbide, zirconia, etc. Examples of the metal material include stainless steel, etc.

[0057] 1.4.4. Second gas separation membrane The second gas separation membrane 52 separates the first space S1 side from the second space S2 side, and allows carbon dioxide (a predetermined gas component) contained in the mixed gas G1 to pass through preferentially compared to gas components other than carbon dioxide. When the rotary fan 4, which is an axial flow fan, rotates, the mixed gas G1 moves in the extension direction of the rotation axis AR (z-axis direction) in the first space S1. The second gas separation membrane 52 is provided downwind of the airflow generated by the rotary fan 4. In the configuration shown in FIG. 1, the z-axis negative side of the blade portion 42 is the downwind. This airflow enhances the gas exchange efficiency on the surface of the second gas separation membrane 52. As a result, even if the concentration of carbon dioxide decreases on the surface of the second gas separation membrane 52 facing the first space S1, it is possible to particularly suppress a decrease in the separation efficiency of carbon dioxide in the second gas separation membrane 52.

[0058] The second gas separation membrane 52 is preferably located on the downwind side, but is not limited to this and may be located in a position other than the downwind side.

[0059] The above description of the first gas separation membrane 51 can also be applied to the second gas separation membrane 52. The second gas separation membrane 52 may be provided as necessary, and may be omitted.

[0060] 1.5.Drive unit The gas separation device 1 includes a drive unit 6 provided inside the second space S2. The drive unit 6 generates a drive force for rotating the rotary fan 4. Since the drive force required to rotate the rotary fan 4 is relatively small, the energy consumption of the gas separation device 1 can be reduced. Therefore, the gas separation device 1 can improve the carbon dioxide separation efficiency while realizing energy conservation.

[0061] 1 includes a motor 61 and a transmission belt 62. The motor 61 rotates a shaft 612. The transmission belt 62 is stretched between the shaft 612 and the base 41, and transmits the driving force to rotate the rotary fan 4.

[0062] In addition to the above elements, the driving unit 6 may have a reducer or the like. Some or all of the elements constituting the driving unit 6 may be omitted. For example, the motor 61 may be provided outside the second space S2.

[0063] 2. Second embodiment Next, a gas separation device according to a second embodiment will be described.

[0064] Fig. 4 is a cross-sectional view showing the configuration of the gas separation device 1 according to the second embodiment. Fig. 5 is a cross-sectional view showing the rotary fan 4 provided in the gas separation device 1 of Fig. 4.

[0065] The second embodiment will be described below, focusing on the differences from the first embodiment and omitting the description of the similarities. Note that in Fig. 4 and Fig. 5, the same reference numerals are used for the same configurations as the first embodiment. The second embodiment is similar to the first embodiment except that the configuration of the rotary fan 4 is different.

[0066] The rotary fan 4 shown in Fig. 4 and Fig. 5 is a centrifugal fan having a base 41, a blade 42, and a first gas separation membrane 51. A centrifugal fan is a fan that generates an airflow along the radial direction (r-axis direction) of the rotation axis AR. This airflow promotes the movement of the mixed gas G1 from the mixed gas supply port 22 toward the negative side of the z axis. This allows new mixed gas G1 to be drawn into the rotary fan 4.

[0067] 4 has a cylindrical shape extending along the rotation axis AR. The end of the base 41 on the z-axis positive side is closed. The inside of the hollow base 41 communicates with the second space S2.

[0068] The blade portion 42 shown in Figs. 4 and 5 has a disk portion 421 that protrudes from the base portion 41 toward the r-axis positive side, and a wing piece 422 that extends from the disk portion 421 toward the z-axis positive side. The disk portion 421 and the wing piece 422 are each hollow. The disk portion 421 may be integral with the base portion 41, but is preferably detachable from the base portion 41. The wing piece 422 may be integral with the disk portion 421, but is preferably detachable from the disk portion 421. This allows the disk portion 421 and the wing piece 422 to be easily removed and attached during maintenance of the rotary fan 4, improving maintainability.

[0069] The first gas chamber 2 shown in Fig. 4 has an outer wall 26. The outer wall 26 has a cylindrical shape that is continuous along the circumferential direction around the rotation axis AR. The outer wall 26 is hollow. The inside of the outer wall 26 communicates with the second space S2 via a communication hole 212 that penetrates the first wall portion 21 and the second wall portion 31.

[0070] An opening is provided on each of the surfaces of the outer wall 26 on the positive side of the r-axis and the negative side of the r-axis. A second gas separation membrane 52 is disposed so as to close the opening. The second gas separation membrane 52 shown in FIG. 4 is disposed downwind of the airflow generated by the rotary fan 4. In the configuration shown in FIG. 4, the positive side of the r-axis of the blade portion 42 is the downwind. This airflow enhances the gas exchange efficiency on the surface of the second gas separation membrane 52. As a result, even if the concentration of carbon dioxide decreases on the surface of the second gas separation membrane 52 facing the first space S1, it is possible to particularly suppress a decrease in the separation efficiency of carbon dioxide in the second gas separation membrane 52.

[0071] The outer wall 26 may be integral with the first wall portion 21, but is preferably detachable from the first wall portion 21. This makes it easier to maintain the outer wall 26.

[0072] 4 and 5, the number of wing pieces 422 of the blade portion 42 may be one, but is preferably multiple, more preferably 4 to 100, and even more preferably 6 to 20. By having multiple wing pieces 422, it is possible to realize a gas separation device 1 with a particularly large gas permeation amount of carbon dioxide. If the number of wing pieces 422 is below the lower limit, the gas permeation amount of carbon dioxide may be reduced. On the other hand, the number of wing pieces 422 may be above the upper limit, but the weight of the rotary fan 4 may increase, and the energy required for rotation may increase.

[0073] In Fig. 5, eight wing pieces 422 are arranged at equal intervals around the rotation axis AR. Furthermore, two first gas separation membranes 51 are provided on one wing piece 422 shown in Fig. 5. The number of first gas separation membranes 51 provided on one wing piece 422 may be one, but preferably multiple. By providing multiple first gas separation membranes 51, a gas separation device 1 with a particularly large gas permeation rate for carbon dioxide can be realized. In the second embodiment as described above, the same effects as in the first embodiment can be obtained.

[0074] The arrangement of the mixed gas supply port 22 and the mixed gas exhaust port 23 may be changed as appropriate depending on the configuration of the rotary fan 4. For example, in this embodiment, the rotary fan 4 is configured to generate an airflow from the rotation axis AR toward the positive side of the r-axis, but it may be configured to generate an airflow in the opposite direction (an airflow from the positive side of the r-axis toward the rotation axis AR). In the latter case, the arrangement of the mixed gas supply port 22 and the mixed gas exhaust port 23 may be reversed from that of this embodiment, that is, the mixed gas exhaust port 23 may be provided on an extension line of the rotation axis AR, and the mixed gas supply port 22 may be provided on the radius of the rotation axis AR.

[0075] 3. Third embodiment Next, a gas separation device according to a third embodiment will be described.

[0076] Fig. 6 is a cross-sectional view showing the configuration of the gas separation device 1 according to the third embodiment. Fig. 7 is a plan view showing the rotary fan 4 provided in the gas separation device 1 of Fig. 6.

[0077] The third embodiment will be described below, focusing on the differences from the first embodiment and omitting the description of the similarities. Note that the same reference numerals are used in Fig. 6 and Fig. 7 to designate the same components as those in the first embodiment. The third embodiment is similar to the first embodiment except that the configuration of the rotary fan 4 is different.

[0078] The rotary fan 4 shown in FIGS. 6 and 7 is an axial fan having a base 41, a blade portion 42, and a first gas separation membrane 51.

[0079] 6 has a cylindrical shape extending along the rotation axis AR. The end of the base 41 on the z-axis positive side is closed. The inside of the hollow base 41 communicates with the second space S2.

[0080] In the blade portion 42 shown in FIG. 6, when the first gas separation membrane 51 is cut on a plane including the rotation axis AR, the angle θ (angle on the second space S2 side) between the rotation axis AR and the cut surface of the first gas separation membrane 51 is different from that in FIG. 1. Specifically, the angle θ shown in FIG. 6 is greater than 90° and less than 180°. That is, in the example shown in FIG. 6, the tip of the blade portion 42 is displaced toward the z-axis positive side from the base end. This makes it possible to generate a stronger airflow toward the z-axis positive side in the first space S1 when the blade portion 42 rotates around the rotation axis AR. As a result, the mixed gas G1 with a low concentration of carbon dioxide can be moved to the mixed gas outlet 23, and new mixed gas G1 with a high concentration of carbon dioxide can be drawn into the rotary fan 4.

[0081] In the first gas chamber 2 shown in FIG. 6, the direction of the airflow of the mixed gas G1 is opposite to that of the first gas chamber 2 shown in FIG. 1. Therefore, in the first gas chamber 2 shown in FIG. 6, a mixed gas supply port 22 is provided in a portion of the first wall portion 21 on the r-axis plus side of the rotary fan 4 (on the radius of the rotation axis AR). This allows new mixed gas G1 to be efficiently drawn into the first space S1. In addition, in the first gas chamber 2 shown in FIG. 6, a mixed gas exhaust port 23 is provided in a portion of the first wall portion 21 on the z-axis plus side of the rotary fan 4 (on the extension line of the rotation axis AR). This allows the mixed gas G1 with a reduced carbon dioxide concentration to be efficiently exhausted to the outside of the first space S1 along with the airflow caused by the rotary fan 4.

[0082] The blade portion 42 shown in FIG. 6 includes four blade portions 42a and four blade portions 42b located on the negative z-axis side of the blade portions 42a. That is, in the rotary fan 4 shown in FIG. 6, the four blade portions 42a and the four blade portions 42b are arranged offset from each other in the z-axis direction. In this configuration, the airflow generated by the blade portion 42b can be directed to the blade portion 42a. This makes it possible to particularly increase the gas exchange efficiency of the mixed gas G1 on the surface of the first gas separation membrane 51 provided on the blade portion 42a.

[0083] In addition, in the rotary fan 4 shown in Fig. 7, the blades 42 are misaligned when viewed from above the rotation axis AR. In particular, in Fig. 7, not only are the blades 42a misaligned with each other and the blades 42b misaligned with each other, but also the blades 42a and 42b are misaligned with each other. This makes it difficult for the airflow to stagnate in the z-axis direction. In the third embodiment as described above, the same effects as in the first embodiment can be obtained.

[0084] 4. Fourth embodiment Next, a gas separation device according to a fourth embodiment will be described.

[0085] Fig. 8 is a plan view showing a rotary fan 4 included in a gas separation device 1 according to the fourth embodiment. Fig. 9 is a schematic diagram in which an example of the flow of mixed gas G1 is added to the cross-sectional view of the blade portion 42 shown in Fig. 8. Fig. 10 is a schematic diagram in which an example of the flow of mixed gas G1 is added to the cross-sectional view of a model (conventional model) in which the convex structures 7 shown in Fig. 9 are omitted.

[0086] The fourth embodiment will be described below, focusing on the differences from the first embodiment and omitting the description of the similarities. Note that in Fig. 8 to Fig. 10, the same reference numerals are used for the same configurations as the first embodiment. The fourth embodiment is similar to the first embodiment except that the configuration of the rotary fan 4 is different.

[0087] The rotary fan 4 shown in Fig. 8 has a convex structure 7. The convex structure 7 is a portion protruding from the surface of the first gas separation membrane 51. In Figs. 8 and 9, the convex structure 7 is provided on the surface of the first gas separation membrane 51, but the convex structure 7 is not limited to this and may be, for example, a portion protruding from the surface of the blade portion 42, or may be a portion protruding from both the surface of the blade portion 42 and the surface of the first gas separation membrane 51.

[0088] The convex structures 7 cause turbulence in the airflow formed on the surfaces of the wing portions 42 and the surface of the first gas separation membrane 51. This turbulence acts to supply new mixed gas G1 to the surface of the first gas separation membrane 51. This makes it possible to maintain a high concentration of carbon dioxide on the surface of the first gas separation membrane 51, and to suppress a decrease in separation efficiency.

[0089] On the other hand, as shown in FIG. 10, when the convex structure 7 is omitted, the airflow of the mixed gas G1 becomes a laminar flow that flows along the surface of the wing portion 42 and the surface of the first gas separation membrane 51. In this specification, the term "laminar flow" refers to an airflow that flows parallel to the surface of an object. The flow rate of the laminar flow tends to decrease closer to the surface of the object. Therefore, in the vicinity of the surface of the first gas separation membrane 51, the gas exchange efficiency of the mixed gas G1 decreases, and the concentration of carbon dioxide decreases. In FIG. 10, the region with a low concentration of carbon dioxide is marked with a dot as a "low concentration region LC". When such a low concentration region LC occurs, the first gas separation membrane 51 does not function sufficiently, and a problem occurs in that the separation efficiency of carbon dioxide decreases.

[0090] In contrast, when the convex structures 7 are provided, as shown in Fig. 9, part of the airflow of the mixed gas G1 hits the convex structures 7, generating turbulence downstream. This turbulence includes, for example, a flow that stirs the mixed gas G1 in the Z-axis direction. For this reason, the effect is that new mixed gas G1 is easily replenished downstream of the convex structures 7, and the carbon dioxide concentration is less likely to decrease. As a result, in the rotary fan 4 shown in Fig. 9, the occurrence of a low concentration region LC as shown in Fig. 10 is suppressed, and a decrease in the carbon dioxide separation efficiency can be suppressed.

[0091] The shape, material, arrangement, etc. of the convex structures 7 are not particularly limited as long as they are components that generate turbulent flow as described above. In FIG. 8, three convex structures 7 are provided on each side of one wing portion 42. The number of convex structures 7 provided on one wing portion 42 may be one or more. By providing multiple convex structures 7, it is possible to generate turbulent flow in each part of the first gas separation membrane 51. As a result, it is possible to particularly suppress a decrease in the separation efficiency of carbon dioxide.

[0092] 5. Advantages of the above embodiment As described above, the gas separation device 1 according to the embodiment includes the first gas chamber 2, the second gas chamber 3, and the rotary fan 4.

[0093] The first gas chamber 2 has a first wall portion 21, a mixed gas supply port 22, and a mixed gas exhaust port 23. The first wall portion 21 defines a first space S1. The mixed gas supply port 22 is provided in the first wall portion 21, and supplies the mixed gas G1 to the inside of the first space S1. The mixed gas exhaust port 23 exhausts the mixed gas G1 from the inside of the first space S1 to the outside.

[0094] The second gas chamber 3 has a second wall 31 and a gas component discharge port 33. The second wall 31 defines a second space S2. The gas component discharge port 33 is provided in the second wall 31, and discharges a gas (mixed gas G2) containing carbon dioxide (a predetermined gas component) extracted from the mixed gas G1 from the inside to the outside of the second space S2. That is, the gas component discharge port 33 discharges a gas obtained by preferentially permeating the carbon dioxide contained in the mixed gas G1 over the other gas components.

[0095] The rotary fan 4 has a hollow base 41, a hollow blade 42, and a first gas separation membrane 51. The base 41 rotates around a rotation axis AR, and the inside of the base 41 is in communication with the second space S2. The blade 42 is disposed in the first space S1, and the inside of the blade 42 is in communication with the second space S2. The first gas separation membrane 51 separates the inside and outside of the blade 42, and allows a gas (mixed gas G2) having a higher concentration of carbon dioxide than the mixed gas G1 to pass through.

[0096] With this configuration, even if the concentration of carbon dioxide on the surface decreases due to the action of the first gas separation membrane 51, the first gas separation membrane 51 provided on the wing portion 42 moves to an area where new mixed gas G1 is present, so that it is possible to suppress the decrease in the concentration of carbon dioxide on the surface of the first gas separation membrane 51. As a result, a gas separation device 1 is obtained in which the decrease in the carbon dioxide separation efficiency of the first gas separation membrane 51 is suppressed.

[0097] Moreover, the gas separation device 1 according to the embodiment includes a drive unit 6 that rotates the rotary fan 4.

[0098] According to such a configuration, it is possible to realize a gas separation device 1 that improves the efficiency of separating carbon dioxide while realizing energy conservation.

[0099] In the gas separation device 1 according to the embodiment, the vane portion 42 is in the form of a plate having a surface (first surface) on the positive side of the z axis and a surface (second surface) on the negative side of the z axis. A first gas separation membrane 51 is provided on each of the surfaces on the positive side of the z axis and the negative side of the z axis.

[0100] According to such a configuration, a plurality of first gas separation membranes 51 are provided on the wing portion 42, so that a gas separation device 1 having a particularly large gas permeation rate for carbon dioxide can be realized.

[0101] In the gas separation device 1 according to the embodiment, the rotary fan 4 has a plurality of blades 42 supported by the base 41 .

[0102] With such a configuration, it is possible to realize a gas separation device 1 that has a particularly large gas permeation rate for carbon dioxide.

[0103] In the gas separation device 1 according to the embodiment, the rotary fan 4 is an axial fan that generates an airflow along the extension direction of the rotation axis AR (z-axis direction).

[0104] According to this configuration, an airflow along the z-axis (airflow toward the positive side or negative side of the z-axis) can be generated in the first space S1. As a result, the mixed gas G1 with a low concentration of carbon dioxide can be moved to the mixed gas outlet 23, and new mixed gas G1 with a high concentration of carbon dioxide can be drawn into the rotary fan 4. Furthermore, when the second gas separation membrane 52 is provided downstream of the airflow, the gas exchange efficiency on the surface of the second gas separation membrane 52 can be increased, and therefore a decrease in the separation efficiency of carbon dioxide in the second gas separation membrane 52 can be particularly suppressed.

[0105] In the gas separation device 1 according to the above embodiment, the blade portions 42 are misaligned with each other when viewed from above the rotation axis AR.

[0106] With this configuration, the airflow is less likely to stagnate in the z-axis direction (the direction in which the rotation axis AR extends).

[0107] Furthermore, in the gas separation device 1 of the above embodiment, when the first gas separation membrane 51 is cut along a plane including the rotation axis AR, the angle between the rotation axis AR and the cut surface of the first gas separation membrane 51 is greater than 0° and less than 90°.

[0108] With this configuration, a stronger airflow toward the negative z-axis side can be generated in the first space S1. As a result, the mixed gas G1 with a low concentration of carbon dioxide can be moved to the mixed gas outlet 23, and new mixed gas G1 with a high concentration of carbon dioxide can be drawn into the rotary fan 4. Furthermore, when the second gas separation membrane 52 is provided downstream of the airflow, the gas exchange efficiency on the surface of the second gas separation membrane 52 can be increased, and therefore a decrease in the separation efficiency of carbon dioxide in the second gas separation membrane 52 can be particularly suppressed.

[0109] In the gas separation device 1 according to the embodiment, the rotary fan 4 is a centrifugal fan that generates an airflow along the radial direction (r-axis direction) of the rotary axis AR.

[0110] According to this configuration, an airflow toward the positive side of the r-axis can be generated in the first space S1. As a result, the mixed gas G1 with a low concentration of carbon dioxide can be moved to the mixed gas outlet 23, and new mixed gas G1 with a high concentration of carbon dioxide can be drawn into the rotary fan 4. Furthermore, when the second gas separation membrane 52 is provided downstream of the airflow, the gas exchange efficiency on the surface of the second gas separation membrane 52 can be increased, and therefore a decrease in the separation efficiency of carbon dioxide in the second gas separation membrane 52 can be particularly suppressed.

[0111] Moreover, the gas separation device 1 according to the embodiment includes a second gas separation membrane 52. The second gas separation membrane 52 is provided downwind of the airflow caused by the rotary fan 4, separates the first space S1 from the second space S2, and allows permeation of a gas (mixed gas G2) containing carbon dioxide (predetermined gas component) extracted from the mixed gas G1.

[0112] This configuration enhances the gas exchange efficiency on the surface of the second gas separation membrane 52. As a result, even if the carbon dioxide concentration decreases on the surface of the second gas separation membrane 52 facing the first space S1, a decrease in the carbon dioxide separation efficiency in the second gas separation membrane 52 can be particularly suppressed.

[0113] Moreover, the gas separation device 1 according to the embodiment includes an exhaust pump 9 connected to the gas component discharge port 33 .

[0114] With this configuration, the second space S2 can be depressurized, and carbon dioxide (a predetermined gas component) contained in the mixed gas G1 can be separated preferentially compared to gas components other than carbon dioxide contained in the mixed gas G1.

[0115] The gas permeability of the first gas separation membrane 51 to carbon dioxide is preferably 5000 GPU or more and 100000 GPU or less.

[0116] With such a configuration, it is possible to realize a first gas separation membrane 51 that can reduce the input amount of energy required for separation, specifically, that can reduce the pressure difference between the first space S1 side and the second space S2 side.

[0117] In the gas separation device 1 according to the embodiment, the mixed gas supply port 22 is disposed on an extension of the rotation axis AR, and the mixed gas discharge port 23 is disposed on the radius of the rotation axis AR.

[0118] With this configuration, new mixed gas G1 can be efficiently drawn into the first space S1 from the mixed gas supply port 22 along with the airflow generated by the rotary fan 4, and the mixed gas G1 with a reduced carbon dioxide concentration can be efficiently discharged outside the first space S1.

[0119] Although the gas separation device according to the present invention has been described above based on the illustrated embodiment, the present invention is not limited to this.

[0120] For example, the gas separation device of the present invention may be one in which each part of the above-mentioned embodiment is replaced with any component having a similar function, or one in which any component is added to the above-mentioned embodiment. [Explanation of symbols]

[0121] Reference Signs List 1...gas separation device, 2...first gas chamber, 3...second gas chamber, 4...rotary fan, 6...drive unit, 7...convex structure, 9...exhaust pump, 21...first wall portion, 22...mixed gas supply port, 23...mixed gas exhaust port, 24...seal bearing, 26...outer wall, 31...second wall portion, 33...gas component exhaust port, 41...base, 42...wing portion, 42a...wing portion, 42b...wing portion, 51...first gas separation membrane, 52...second gas separation membrane, 61...motor, 62...transmission belt, 212...communication hole, 214...communication hole, 421...disk portion, 422...wing piece, 612...shaft, AR...rotating shaft, D...outer diameter, G1...mixed gas, G2...mixed gas, LC...low concentration region, S1...first space, S2...second space, t...thickness, θ...angle

Claims

1. a first gas chamber including a first wall portion defining a first space, a mixed gas supply port provided in the first wall portion for supplying a mixed gas into the first space, and a mixed gas discharge port for discharging the mixed gas from the inside of the first space to the outside; a second gas chamber including a second wall portion defining a second space and a gas component exhaust port provided in the second wall portion and configured to exhaust a gas containing a predetermined gas component extracted from the mixed gas from the inside of the second space to the outside; a rotary fan that rotates about a rotation axis and has a hollow base, the interior of which communicates with the second space, a hollow blade portion that is disposed in the first space and the interior of which communicates with the second space, and a first gas separation membrane that separates the inside and outside of the blade portion and allows a gas having a higher concentration of the predetermined gas component than the mixed gas to pass through; A gas separation device comprising:

2. The gas separation device according to claim 1 , further comprising a drive unit for rotating the rotary fan.

3. The wing portion has a plate shape having a first surface and a second surface, The gas separation device according to claim 1 or 2, wherein the first gas separation membrane is provided on each of the first surface and the second surface.

4. The gas separation device of claim 1 , wherein the rotary fan has a plurality of the blades supported on the base.

5. The gas separation device according to claim 4 , wherein the rotary fan is an axial flow fan that generates an airflow along an extension direction of the rotary shaft.

6. The gas separation device according to claim 5 , wherein the blade portions are offset from each other when viewed from above the rotation shaft.

7. The gas separation device described in claim 5, wherein when the first gas separation membrane is cut on a plane including the rotation axis, the angle between the rotation axis and the cut surface of the first gas separation membrane is greater than 0° and less than 90°.

8. 5. The gas separation device according to claim 4, wherein the rotary fan is a centrifugal fan that generates an air current along a radial direction of the rotary shaft.

9. A gas separation device as described in claim 5 or 8, comprising a second gas separation membrane that is arranged downwind of the airflow generated by the rotating fan, separates the first space from the second space, and allows gas containing the specified gas component extracted from the mixed gas to pass through.

10. The gas separation device according to claim 1 or 2, further comprising an exhaust pump connected to the gas component discharge port.

11. 3. The gas separation device according to claim 1 or 2, wherein the first gas separation membrane has a gas permeability to carbon dioxide of 5,000 GPU or more and 100,000 GPU or less.

12. the mixed gas supply port is disposed on an extension line of the rotation shaft, 3. The gas separation device according to claim 1, wherein the mixed gas outlet is disposed on a radius of the rotation shaft.

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